Add command to create rascal location from selection

rascal-vscode-extension/package.json

@@ -46,8 +46,25 @@
       {
         "command": "rascalmpl.importMain",
         "title": "Start Rascal Terminal and Import this module"
+      },
+      {
+        "command": "rascalmpl.copyLocation",
+        "title": "Copy Location of Selection to Clipboard"
+      }
+    ],
+    "keybindings": [
+      {
+        "command": "rascalmpl.copyLocation",
+        "key": "shift+alt+l",
+        "mac": "shift+cmd+l"
       }
     ],
+    "menus": {
+      "editor/context": [{
+        "command": "rascalmpl.copyLocation",
+        "group": "editor/context"
+      }]
+    },
     "languages": [
       {
         "id": "rascalmpl",

rascal-vscode-extension/src/RascalExtension.ts

@@ -34,6 +34,7 @@ import { RascalLanguageServer } from './lsp/RascalLanguageServer';
 import { LanguageParameter, ParameterizedLanguageServer } from './lsp/ParameterizedLanguageServer';
 import { RascalTerminalLinkProvider } from './RascalTerminalLinkProvider';
 import { VSCodeUriResolverServer } from './fs/VSCodeURIResolver';
+import {utf8to16Offset, utf8to16Length, utf8to16Column} from "./RascalTerminalLinkProvider";
 
 export class RascalExtension implements vscode.Disposable {
     private readonly vfsServer: VSCodeUriResolverServer;
@@ -51,6 +52,8 @@ export class RascalExtension implements vscode.Disposable {
         this.registerMainRun();
         this.registerImportModule();
 
+        this.registerCopyLocation();
+
         vscode.window.registerTerminalLinkProvider(new RascalTerminalLinkProvider(this.rascal.rascalClient));
     }
 
@@ -99,6 +102,38 @@ export class RascalExtension implements vscode.Disposable {
         );
     }
 
+
+    private registerCopyLocation() {
+        this.context.subscriptions.push(
+            vscode.commands.registerTextEditorCommand("rascalmpl.copyLocation", (text, _edit, moduleName) => {
+                const editor = vscode.window.activeTextEditor;
+                if (editor) {
+                    const uri = editor.document.uri.toString();
+                    const selection = editor.selection;
+
+                    let offset = editor.document.offsetAt(selection.start);
+                    let offsetUtf16 = utf8to16Offset(editor.document, offset);
+
+                    let length = editor.document.getText(selection).length;
+                    let lengthUtf16 = utf8to16Length(editor.document, offset, offset+length);
+
+                    // the startline is not affected by UTF8 or UTF16, because line breaks are never UTF16
+                    let startLine = selection.start.line;
+                    let endLine = selection.end.line;
+
+                    let startColumn = selection.start.character;
+                    let startColumnUtf16 = utf8to16Column(editor.document, startLine, startColumn);
+                    let endColumn = selection.end.character;
+                    let endColumnUtf16 = utf8to16Column(editor.document, endLine, endColumn);
+
+                    const location = `|${uri}|(${offsetUtf16},${lengthUtf16},<${startLine+1},${startColumnUtf16}>,<${endLine+1},${endColumnUtf16}>)`;
+
+                    vscode.env.clipboard.writeText(location);
+                }
+            })
+        )
+    }
+
     private startTerminal(uri: vscode.Uri | undefined, ...extraArgs: string[]) {
         return vscode.window.withProgress({
             location: vscode.ProgressLocation.Notification,

rascal-vscode-extension/src/RascalTerminalLinkProvider.ts

@@ -177,3 +177,37 @@ function fixedOffsetLengthPositions(td: vscode.TextDocument, offset: number, len
     }
     return [offset, endOffset];
 }
+
+/**
+ * Convert the length of a selection from a UTF-8-based count (used by VS Code) to a UTF-16-based count (used by Rascal).
+ * Note how this function also works for calculating offsets by setting `begin` to 0.
+ * @param td the text document in which the selection was made
+ * @param endUtf8 the end position (UTF-8) of the selection
+ * @param beginUtf8 the begin of the selection (UTF-8)
+ * @returns length of the selection when counted as UTF-16.
+ */
+function utf8to16Conversation(text: string, beginUtf8: number, endUtf8: number): number {
+    let lengthUtf16 = endUtf8 - beginUtf8;
+
+    for (let i = beginUtf8; i < endUtf8-1; i++) {
+        const c = text.charCodeAt(i);
+        if (isHighSurrogate(c) && isLowSurrogate(text.charCodeAt(i + 1))) {
+            lengthUtf16--;
+        }
+    }
+
+    return lengthUtf16;
+}
+
+export function utf8to16Offset(td: vscode.TextDocument, offsetUtf8: number): number {
+    return utf8to16Conversation(td.getText(), 0, offsetUtf8);
+}
+
+export function utf8to16Length(td: vscode.TextDocument, beginUtf8: number, endUtf8: number): number {
+    return utf8to16Conversation(td.getText(), beginUtf8, endUtf8);
+}
+
+export function utf8to16Column(td: vscode.TextDocument, line: number, columnUtf8: number): number {
+    const fullLine = td.lineAt(line).text;
+    return utf8to16Conversation(fullLine, 0, columnUtf8);
+}